This page is updated with new research (including new retrospective analyses) on HER2-positive invasive breast cancer sized at T1a or T1b, and also for DCIS with microinvasion (T1mic). It is updated about once a month, or more often as needed.
The St. Gallen conference was held in Vienna in 2019, and in June, a panel of German doctors voted on standards of care. “Patients with HER2-positive (HER2+) breast cancer receive anti-HER2-targeted therapy in addition to chemotherapy. This applies starting at stage I, however this is not a standard in T1a carcinomas without lymph node involvement (N0) (majority vote (55.3%). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6570611/
In December 2018, the National Comprehensive Cancer Network published a new study in its professional journal. The short abstract conclusion recommended no chemo or trastazumab for T1mic and T1a HER2-positive tumors. Here is the link to the short abstract for non-members: http://www.jnccn.org/content/16/11/1311.short
- Note: I emailed the lead author and requested a full copy of his findings, which he was kind enough to share with me. While I cannot post his work here, I bet he would share his research with other patients. His email can be found at the link above.
November 11, 2018 issue of “Cancer Reports” – this is a large retrospective study that examines the usefulness of using 1 centimeter as a cut-off point for the sub-classification of the T1 size: https://onlinelibrary.wiley.com/doi/full/10.1002/cam4.1785
August 2018 – this study finds radiation with lumpectomy and also mastectomy can lower risk of recurrence. One author, Steven A. Narod, MD, does a lot of research with DCIS. Association of Radiotherapy With Survival in Women Treated for Ductal Carcinoma In Situ With Lumpectomy or Mastectomy: https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2696506
July 2018 – a study in the official journal for the National Comprehensive Cancer Network found no benefit of adjuvant chemotherapy for patients with HER2-positive T1mic or T1a tumors: http://www.jnccn.org/content/16/11/1311.short (only the short version is available to non-subscribers)
January 2018 – this study found patients with T1a HER2+ tumors discovered in between breast cancer screenings (mammogram/sonogram), had a higher likelihood of developing a recurrence (75% to 93%) and therefore should strongly consider chemotherapy and HER2 targeted treatment: https://www.sciencedirect.com/science/article/pii/S0959804917313643
July 2017 – a giant retrospective study of 104,499 cases of node-negative T1a, T1b, T1c, T2, and T3 breast cancers found “T1a tumors have the same risk of mortality regardless of ER/PR/HER2 subtype, and ER and PR negativity plays a stronger role in survival than HER2 positivity for tumors of all sizes”: https://www.ncbi.nlm.nih.gov/pubmed/28689363
The information contained in this blog is not intended to be used for medical diagnosis or treatment. It should not be used in place of the advice of your doctor or other qualified health care provider.